CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015	[1]
Current assets:
Cash and cash equivalents	$ 151,778	$ 159,180
Short-term marketable securities	16,414	28,103
Related party receivables from collaborative arrangements	27,539	26,228
Prepaid expenses and other current assets	975	814
Total current assets	196,706	214,325
Property and equipment, net	193	221
Capitalized fees paid to a related party, net	190,912	194,368
Other assets	18	18
Total assets	387,829	408,932
Current liabilities:
Accounts payable	576	818
Accrued personnel-related expenses	913	1,659
Accrued interest payable	6,562	7,911
Other accrued liabilities	1,687	2,218
Deferred revenue	885	885
Total current liabilities	10,623	13,491
Convertible subordinated notes, due 2023	251,124	250,992
Non-recourse notes, due 2029	483,389	482,139
Other long-term liabilities	1,784	1,856
Deferred revenue	$ 2,878	$ 3,099
Commitments and contingencies (Notes 3, 6 and 9)
Stockholders' deficit:
Preferred stock: $0.01 par value, 230 shares authorized, no shares issued and outstanding
Common stock: $0.01 par value, 200,000 shares authorized, 113,146 and 114,933 shares issued as of March 31, 2016 and December 31, 2015, respectively	$ 1,132	$ 1,149
Treasury stock: 150 shares as of March 31, 2016 and December 31, 2015	(3,263)	(3,263)
Additional paid-in capital	1,328,155	1,351,898
Accumulated other comprehensive loss	(1)	(2)
Accumulated deficit	(1,687,992)	(1,692,427)
Total stockholders' deficit	(361,969)	(342,645)
Total liabilities and stockholders' deficit	$ 387,829	$ 408,932

[1] Condensed consolidated balance sheet as of December 31, 2015 has been derived from audited consolidated financial statements.